Already an infamously brutal Congolese warlord at just 24, Germain Katanga was found guilty yesterday of being an accessory to war crimes, including murder and pillage – only the second conviction in the 12-year history of the International Criminal Court (ICC).

At the end of a six-year trial, one of the longest in the court’s history, Katanga (36) was convicted of complicity in an attack on the village of Bogoro in northeast Congo in February 2003, in which all 200 inhabitants were massacred with guns and machetes while they slept.

AcquittedHowever he was acquitted on charges of rape, sexual slavery and using child soldiers during the vicious ethnic struggle for control of the diamond-rich province of Ituri from 1999 to 2003, in which an estimated 50,000 people died.

Known as “Simba” for his uncompromising ferocity, two of the three judges found that Katanga, alleged leader of Patriotic Resistance Force in Ituri (FRPI), had supplied the guns used by Lendu and Ngiti fighters against largely unarmed Bogoro civilians of Hema ethnicity.

Roads from the strategically important village were blocked by the attackers in order to kill any civilians attempting to escape. The inhabitants, including women and children, were then hacked or shot to death — or burned alive inside their homes. Nobody survived.

The court in The Hague found that the manner in which the attack was carried out led it to believe that the civilian population was deliberately targeted.

Without the weapons supplied by Katanga, the attackers “would not have been able to carry out the attack with such efficiency”, said presiding judge Bruno Cotte.

However, in a dissenting opinion, Judge Christine van den Wyngaert said the trial had lasted too long, and that Katanga should have been acquitted along with his co-accused, Mathieu Ngudjolo – who was freed in December 2012 due to doubts about the evidence of key prosecution witnesses.

She also contended that it was unfair to convict Katanga as an accessory when he had originally been charged with being central to the commission of the crimes. Changing the nature of the charges had deprived him of the ability to defend himself, she argued.

LessonsGeraldine Mattioli-Zeltner, a legal expert at Human Rights Watch, agreed that the change meant “the ICC should draw lessons from this and other cases when it comes to charging and modifying charges against suspects”.

Katanga remains in custody and will be sentenced at a separate hearing at which he could be jailed for up to 30 years. He is expected to appeal against the convictions.

In July 2012, Thomas Lubanga, a rival militia leader in Ituri – the only other person convicted by the ICC – was sentenced to 14 years in jail for recruiting and using child soldiers.